Eat your heart out : Phrases

Heart is also defined as the central, core, or inner most part of an object (or person). To eat the heart out is to remove the core or most important part, a part that will surely be missed. The phrase is probably a shortened way of saying This will eat your heart out.

Alternative: Adapted from the 16th century eat one's own heart meaning to suffer from silent grief or vexation. It also has roots in the Biblical phrase to eat one’s own flesh used to describe an indolent person.